Collaborative Research: Extending leaf functional trait ecology to leaf symbionts

丰富多样的真菌生活在所有树木健康的叶子中。这些“真菌内生菌”（endo，内部；phyte，植物）在逆境条件下对促进植物健康很重要。然而，在不同植物物种中发现的不同内生菌群落的形成因素尚未得到很好的理解。该项目的总体目标是将真菌内生菌整合到我们对热带植物生态学的理解中，特别关注叶片性状，植物生产力以及植物防御攻击叶片的昆虫和病原体的能力之间的关系。提高我们对真菌内生菌的理解是很重要的，因为它们影响植物的生产力和对干旱和疾病等环境胁迫的抵抗力，包括对具有经济重要性的植物。研究结果将有助于利用内生菌来缓解植物对快速变化的世界的反应，并在可持续农业和森林管理中有潜在的应用。该项目还将支持本科生和研究生的跨学科研究培训，包括代表性不足群体的学生，为K-12教师和高中生提供指导研究经验，并促进公众宣传。在热带森林的背景下，叶片性状和内生菌高度多样化，本项目将测试以下假设：(1)叶片中内生菌群落的变化与与生长和持续策略相关的叶片性状有关；(2)内生真菌会影响叶片和植物的功能；(3)内生菌对植物防御的贡献随叶片性状的变化而变化；(4)通过整合这些叶面共生体，可以极大地了解植物的生长与持久性策略。研究方法包括实地观察和实验以及生物分析。计划在12个焦点种中对内生菌群落进行野外试验。此外，将这12个物种的叶子引入切叶蚁，以测试寿命较长的物种对切叶蚁的吸引力是否较低，以及这是否由内生菌负荷介导。此外，将病原体引入12个焦点物种，以测定内生菌负荷高的叶片的损害是否较低。

Abundant and diverse fungi live inside healthy leaves of all trees. These 'fungal endophytes' (endo, inside; phyte, plant) can be important in enhancing plant health under stressful conditions. However, the factors that shape the diverse communities of endophytes found in different plant species are not well understood. This project's overall goal is to integrate fungal endophytes into our understanding of tropical plant ecology, with a special focus on the relationships among leaf traits, plant productivity, and the ability of plants to defend against insects and pathogens that attack leaves. Improving our understanding of fungal endophytes is important since they influence plant productivity and resistance to environmental stresses such as drought and disease, including for plants of economic importance. Results will facilitate use of endophytes in mitigating plant responses to a rapidly changing world, with potential applications in sustainable agriculture and forest management. This project will also support the training of undergraduate and graduate students in interdisciplinary research, including students of under-represented groups, provide mentored research experiences for K-12 teachers and for high school students, and contribute to public outreach.In the context of tropical forests, where leaf traits and endophytes are highly diverse, this project will test the hypotheses that (1) endophyte communities in leaves vary in relation to leaf traits associated with growth vs. persistence strategies; (2) endophytes will influence leaf and plant functions; (3) contribution of endophytes to plant defense will vary as a function of leaf traits; and (4) understanding growth vs. persistence strategies of plants can be informed greatly by integration of these foliar symbionts. The research approach involves field observations and experiments as well as bioassays. A field experiment is planned where endophyte communities are manipulated in 12 focal species. Additionally, leaves from these same 12 species will be introduced to leaf cutter ants to test whether longer lifespan species are less attractive to leaf cutter ants, and whether this will be mediated by endophyte load. Furthermore, pathogens will be introduced to the 12 focal species to assay if damage will be lower in leaves with high endophyte loads.